Process of binding the active material of positive-pole lead electrodes.



- and capable of forming complex anions with UNITED srATEs PATENT clar on.

WILLIAM Monmsoir, or nus VMOINES, IOWA. a

rnocnss or BINpIN THE aorrvn MATERIAL or POSITIVE-POLE LEAD nnncrnonns.

1,021,995. No Drawing.

Tomllwhom'it may concern Y Be it known that I, VSTILLIAM MORRISON, a citizen of the United States, residing at DesMoines,'in the county of Polk and State of Iowa, have invented certain new and use'. ful Improvements .in Processes of Binding la poundlof a metal incapable of directly rcplacing'h drogen "n a sulfuric acid solution; "inso uble by anodic oxidation ina sulfuric acid solution; incapable of cathodic reduction to .metal, or ofelectrolytic sepa rat-ion as metal, in a sulfuric acid solution;

electronegative elements, which can constitute the acidicrradical of compounds having lead asa base. The three known metals which have these characteristics are tungr sten, tantalum and niobium, otherwise called columbium. c

To illustratethe inventifc'gn, there will first be described an electrolytic process of producing a lead-peroxid electrode employing a compound of tantalum as the binder. For this purpose, a metallic support, for example a grid of antimonial lead, is pasted or filled with the usual mixture of minium, 'litharge and a sulfuric acid solut1on,'in

which mixture lead sulfate forms as a provisionalbinder. Complete formation, or 'peroxidation, of the active material 1s then preferably initiallyefiected-by placlng the pasted grids,,alternately with unfilled grids serving as dummy electrodes of the opposite polarity, in a sulfuric acid solution having a specific gravity ofr1.200 to 1.250 and passin an electric current through the solution, .a terna tely in opposite directions, until the paste has been sufiiciently expanded, care bein taken not to force the discharge beyon ithe normal intended capacity of the electrodes; The formed and dummy electrodes are thenremoved fiom the sulfuric acid solution and pbced in'a cell containing Water, and 'electriq-scurrent is passed from the filled electrodes to/the dummies until the free aci-dintl1e activematerial has been removed. The electrodes and dummles are then removed, rinsed in'water, and placed v Specification of, Letters Patent.

- 'in a strong aqueous solution of an alkalimetal tantalatefloi example potassium hexa tantalate. An electric current is then passed from the filied electrodesthrough the solution to the dummies, and is continued for .Pat entedApin2, 1912. Application filed February 24, 1912. Serial No. 679,702. i

several hours, thereby causing tantalum ions, presumably complex tantalum-oxygen ions, to penetrate the active material to any dpsired degree and tocombine chemically gwith the lead-oxygen compounds thereof, and particularly with the lead sulfate which serves as the provisional binder in the elec t-rode. The electrodes and dummies are then removed, rinsed in Water, placed in a sulfuric acidsolution having a specific gravity or about 1.300, and an electric current is passed from the electrodes to the dummiesv until. all of the soluble constituents of, the active material have been removed or rendered insoluble. The electrodes are then dlscharged to theextent of their normal ca pacity, and thereafter recharged,- preferably to somewhat less than their full capacity, in

another sulfuric acid solution of 1.280 speclfic gravity, the efiect of such incomplete,

rechargingbeing to leave in the plate a cer tain proportion of lead sulfate to combine with the tantalum ions on a repetition of the treatment, should such repetition be desi d, for the purpose of'impregnating the actlve material with an additional amountfof the bindercompound. At the conclusion of the treatment the positive-pole electrodes are mounted in connection with. the regular negative plates, and receive their full normal charge;

The object of uerforming the preceding operations with dummyelectrodes. instead of with the regular battery electrodes is to prevent injury to the latter by absorption of the tantalum compound or by deposition of rimpuritiestherein. i o 7 Positiveepole electrodes pre'pared as d'ee scribed are not suited for forming negative electrodes by reversal, since negative electrodes thus formed undergo discharge by local action.' Neverthelesspany accidental, I reversal causes no particulaminjury t ale The ,tantalum-oxygen 'anion appears vto electrode;

play, the same role in the binder compound as does the sulfur oxygen anion in the ordi nary llead electrodes in which lead sulfate} constitute the binder. .The leadstantalume oxygen-compound is however, ascompared with the lead sulfate heretofore commonly used "as a binder, very permanent and insoluble. The tantalum compound has a very great capacity for binding sulfuric acid, in charging a. battery having positivepole electrodes bound by such compound The electrolytic method of binding the active material especially impregnates the superficial portions with the binder, thereby giving it a shell or crust of active material permanentlyand durably bound by a very insoluble compound.

The initial formation of the electrodes may be omitted and the filled grids may be at once treated in the tantalum solution to impregnate the active material with the binder, formation being subsequently effected. Such subsequent formation, however, consumes a much larger amount of current than does initial formation.

Positive-pole electrodes having a binder containing both tantalum and niobium may be prepared by the method above described,

.a mixture of a soluble tantalum and niobate being used as the electrolyte. As these two metals commonly occur together in ores, and as it is difficultand expensive to separate 'them, it is often commercially preferable to thus use both in the binder.

WVhile the described electrolytic process of impregnation is an e fiieient and operative one, it is sometimes preferable, particularly with thick plates, in order to more uniformly distribute the binder throughout the active mass, to incorporate a portion of the binder with the active material by another method, which-will now be described. This method consists in forming an aqueous solution of a suitable lead salt, as lead nitrate or or more, is very thoroughly mixed with the minium-litharge paste, as by grinding the materials together. The positive-pole electrode treated by this preliminarymethod should receive a prolonged and strong charg-j ing treatment in sulfuric acid, with dummy negatives, before assembling in the'battery, in order to remove or to render-insoluble any remaining soluble components of the The electrode is then finished by the plate. electrolytic method heretofore described, that is, by connecting it as theanode in. a

solution of a tantalate, or tantalate an'dniobate, to impregnate the active material, and especially the outer portions thereof, with a binder-compound containing tantalum or tantalum and niobium.

It is to be understood that the several foregoing examples are illustrative in ehal' acter, and that the invention is not limited to the details of manipulation or to the strength or proportions of reagents recited; and it- 'is also to be understood that the positive-pole electrodes ma be prepared by methods other thanthose herein specifically described without departure from my invention. The active material of Plant electrodes, formed out of solid lead, may alsobe bound employinglthem as anodes in a solution of a tantalate or a tantalate and niobate.

I claim:

1. In a process of binding the active material of positive-pole lead electrodes, the step which consists in electrolytically impregnating the active material with a compound containing tantalum in its acidic radical. I 'j' 2. In a process of bindiitg the active material of positive-pole lea 'd electrodes, the step which consists inelectrolytically im pregnating the active material with compounds'containing tantalum and niobium in Y their acidic radicals.

3. In a process of binding the active material of positive-pole lead electrodes, the step which consists in passing an electric current from the electrode through a solution of a tantalate, thereby impregnating the active material with a tantalum compound.

4. The process of binding the active materialof positive-pole lead electrodes, which consistsin passing an electric current from the electrode through a solution ofa tantalate thereby impregnating the active material with a tantalum compound, and thereafter reacting onsaid compound with sulfuricaoid.

Si-The process of binding the active material of positive-pole lead electrodes, which consists in passing an electric current from the electrode through a solutionof atantalate, thereby impregnating the active material with a tantalum compound, and thereafter electrochemically reacting on said compound with sulfuric acid.

6. The process of binding the active material of positive-pole lead electrodes, which consists in passing an electric current from the electrode through a solution of a tantalate and a niobate,,thereby impregnating the active material with tantalum and nio bium compounds, and thereafter reacting on said compounds with sulfuric acid.

7 The process of binding the active material of positive-pole lead electrodes, which consists'in reacting on a solution of a lead salt with a' compound of tungsten, mixing the reaction-product with the active material, applying the mixture to a support to constitute an electrode, and electrolytically consists 1n passing an electric current from the electrode through a solution ofa tantalate, thereby im regnating the active material with a tanta um compound, and thereafter electrochemically reacting on said compoundwith sulfuric acid.

9. The process of binding the active ma,- terial, of positive-pole lead electrodes, which consists in assing an electric current from the electr e through a solution ofa tantalate and a niobate, thereby impregnating the active material with tantalum and niobium compounds, and thereafter electrochemically reacting .on said compounds with sulfurlc;

acid. v 1 0. The process of bindin vthe active material of positive-pole lead e ectrodes, whichconsl'sts in reacting on a solution of a lead"- salt with a com ound of tungsten, heating the reaction-pro not and mixing it. with active materlal, applying the mixture to a [SEAL] i ort to constitute an electrode,

g s an e ectrlc current from the electrode t ougha solution of a tantalate, thereby impregnating the activematerial with a compound 7 of tantalum,'and electrochemically reacting on said compound with sulfuric acid.

I 11. The process ofbindin the active material f positive-polelad e 'e'ctrodes, which consists m-reacting on a solution of a-lead salt with a, com ound of tungsten, heating the reactionrpro notand mixing it with the active mater1al, applying the mixture to a support to constitute an electrode, passing r -an electric current from the electrode.

through. a solution of a- .tantalate and a niob'ate, thereby .impre ating the active material with compoun of tantalum and niobium, and electrochemically reacting on said compounds with sulfuric acid, In testimqn .Jwhereof I aflix my signature in presence 0 two witnesses. H. WILLIAM.MORRISON.

,Witnesses: w I 'EUommA'. Bnmns,

Jos.. H. Bmoxwoop,

ih ih hereby certifiedthalt rhh iih rahshi No. 1,621,995, giants a n- ,2, ,1912', upon the application of Morrison,- of Moines, Iowa, for an improvement in lr liinding-the Active Material i of Positive-Pole Lead Electrodes, an error appear' the printedlspecification requiring correction as follows: Page 2, line 23, forftheword mhthlh ta tantalate; Ihhd that the said Letters Patent should, this correction therein that the same may conform to the record or the case in the Paten'tOfiice,

C. C. BILLINGS, Acting Commissioner of Patents.

consists 1n passing an electric current from the electrode through a solution ofa tantalate, thereby im regnating the active material with a tanta um compound, and thereafter electrochemically reacting on said compoundwith sulfuric acid.

9. The process of binding the active ma,- terial, of positive-pole lead electrodes, which consists in assing an electric current from the electr e through a solution ofa tantalate and a niobate, thereby impregnating the active material with tantalum and niobium compounds, and thereafter electrochemically reacting .on said compounds with sulfurlc;

acid. v 1 0. The process of bindin vthe active material of positive-pole lead e ectrodes, whichconsl'sts in reacting on a solution of a lead"- salt with a com ound of tungsten, heating the reaction-pro not and mixing it. with active materlal, applying the mixture to a [SEAL] i ort to constitute an electrode,

g s an e ectrlc current from the electrode t ougha solution of a tantalate, thereby impregnating the activematerial with a compound 7 of tantalum,'and electrochemically reacting on said compound with sulfuric acid.

I 11. The process ofbindin the active material f positive-polelad e 'e'ctrodes, which consists m-reacting on a solution of a-lead salt with a, com ound of tungsten, heating the reactionrpro notand mixing it with the active mater1al, applying the mixture to a support to constitute an electrode, passing r -an electric current from the electrode.

through. a solution of a- .tantalate and a niob'ate, thereby .impre ating the active material with compoun of tantalum and niobium, and electrochemically reacting on said compounds with sulfuric acid, In testimqn .Jwhereof I aflix my signature in presence 0 two witnesses. H. WILLIAM.MORRISON.

,Witnesses: w I 'EUommA'. Bnmns,

Jos.. H. Bmoxwoop,

ih ih hereby certifiedthalt rhh iih rahshi No. 1,621,995, giants a n- ,2, ,1912', upon the application of Morrison,- of Moines, Iowa, for an improvement in lr liinding-the Active Material i of Positive-Pole Lead Electrodes, an error appear' the printedlspecification requiring correction as follows: Page 2, line 23, forftheword mhthlh ta tantalate; Ihhd that the said Letters Patent should, this correction therein that the same may conform to the record or the case in the Paten'tOfiice,

C. C. BILLINGS, Acting Commissioner of Patents.

Correction in Letters Patent No. 1,021,995.

It is hereby certified mun n w Patent 1%. 1,021,995, granted April 2,

1912, upon the application of William Morrison, of Des Moines, Iowa, for an improvement in Processes of Binding the Active Material of Positive-Pole Lead Electrodes, an error appeal?! in the printed specification requiring correction as follows: Page 2, line 23, forfthe word tantalum read tantalate; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflioe.

Signed and sealed this 21st day of May, A. D., 1912.

mo 0. c. BILLINGS,

Acting Commissioner of Patents. 

